This invention relates generally to an apparatus for mounting chip type circuit elements on a printed circuit board and, in particular, to an apparatus for mounting chip type circuit elements which do not have lead wires associated therewith on a printed circuit board in a serial or one-by-one fashion.
U.S. Pat. No. 4,292,116 issued Sept. 29, 1981, assigned to the same assignee as the instant application, discloses an apparatus for mounting chip type circuit elements on a printed circuit board. Such apparatus includes a suction plate adapted to pick up and hold a multiplicity of chip type circuit elements and convey the same to a printed circuit board on which they are to be mounted.
Such mounting apparatus which incorporates the suction plate described above has a disadvantage in that it is difficult to utilize the same when it is desired to mount the chip type circuit elements after electronic elements having lead wires are inserted into the printed circuit board.
U.S. patent application Ser. No. 266,109, filed May 21, 1981, assigned to the same assignee as the instant application, discloses an apparatus for mounting chip type circuit elements on a printed circuit board in one-by-one fashion. Such apparatus includes a supply unit adapted to supply chip type circuit elements, a plurality of pallets adapted to be conveyed in an intermittent fashion in a longitudinal direction, sequence heads adapted to shift the circuit elements onto the pallet, an X-Y table adapted to support a printed circuit board, a mounting mechanism having mounting heads associated therewith for mounting the chip type circuit elements on the printed circuit board supported by the X-Y table and a shifting head for picking up the chip type circuit elements from the pallets and delivering the same to the mounting heads of the mounting mechanism. The pallets which are adapted to carry the chip type circuit elements include an adhesive mat which forms the surface for carrying the chip type circuit elements. The sequence head, mounting head and the shifting head each utilizes only suction force for holding the chip type circuit element.
Such mounting apparatus which incorporates the pallets described above has a disadvantage in that it is difficult to reliably prevent positional deviations of the chip type circuit elements or rotation of the same during operation, especially during high-speed transference.
Further, in apparatus for shifting and mounting chip type circuit elements on a printed circuit board which utilizes only suctioning of the circuit element, it is not uncommon for the circuit element to deviate from its desired position. Where such positional deviations are unduly large, the electrodes of the circuit element may be spaced by an undesirable amount from the conductor pattern printed on the circuit board resulting in various problems such as failure of connections.